Such systems are used as vehicle navigation systems, for example. They include as the positioning unit a receiver for a satellite signal such as a GPS signal, which may be analyzed to obtain information regarding the current geographic position of the vehicle equipped with the navigation system with high accuracy. By comparing this position information with information stored in a map unit, such a system is capable of discovering from a plurality of routes, about which information is stored in the map unit, precisely that route on which the vehicle is located, and displaying the current position of the vehicle on a display screen via an interface unit, e.g., a map of the surrounding area. Such systems frequently also include an arrangement by which a user may input a destination into the system, whereupon the system selects a route to the desired destination on the basis of the information stored in the map unit and provides the driver continuously with information needed to follow this route in the course of the trip by drawing the attention of the driver (before reaching a turn) to the fact that he must leave the road on which he is currently driving and in which direction he must continue driving.
However, the information provided by the majority of such systems is limited to the minimum needed by a driver to follow a given route.
A first step in this direction of expanding the capabilities of these conventional information and control systems was discussed in German Published Patent Application No. 195 48 487, where the current position information obtained by a positioning unit with the help of a satellite signal and the information supplied by a map unit regarding the course of a route are used to control the alignment of the headlights of a vehicle adapted to the course of the road ahead of that is currently being traveled so that the headlights of the vehicle are deflected to the side even before reaching a curve to thereby illuminate the road in front of the vehicle for a longer distance than would be possible with traditional headlights.
This conventional system includes a control unit which receives information from the positioning unit regarding the current position of the vehicle and information from the map unit regarding the course and local topology of the road on which the vehicle is currently positioned. On the basis of the information regarding the course of the road in front of the vehicle, the control unit calculates continuously the required and/or optimum light distribution of the headlight system and controls the headlights accordingly.
This system requires a considerable computing power because the radius of curvature of the road in front of the vehicle must be constantly calculated in advance. Furthermore, its applicability is limited to controlling the vehicle headlights.